The plant kingdom is made up of living beings who have played a key role in the formation of life in the world. Without plants, the massive production of oxygen now in the atmosphere, all generated from carbon dioxide, would not have been possible, which has allowed the emergence of other classes of multicellular beings such as animals. In addition, they are the main source of food for many organisms.
Plants have the ability to grow as well as the ability to feel, even though they don’t do it the same way animals do, or feel pain. They can detect changes on the outside and “learn” from those experiences. For example, there is phototropism, which is the ability to direct growth in the direction of light rays. But, Can plants have a sense of vision similar to that of humans? This is an idea that has been categorically denied by scientists for decades, but recent studies provide evidence against this belief.
The possible vision of plants
The hypothesis that plants have the ability to see is not new. Already in 1907, botanist Francis Darwin, Son of the naturalist and father of the theory of evolution Charles Darwin, reflects on it. Known for his studies of the aforementioned phototropism, Francis hinted that there could be an organ formed by the combination of a cell that acts like a lens and another that is sensitive to light, providing the function of see.
Experiments from the beginning of the 20th century have proven the existence of an organ that we know today as the ocel, or simple eye, But that is present in invertebrates and not in plants. Therefore, the idea of vision in plants fell into oblivion … until the end of last year, when with the emergence of a new line of research the idea was revived.
A bacteria with sight
A recent Trends in Plant Science publication by František Baluska, plant cell biologist at the University of Bonn in Germany, and Stefano Mancuso, plant physiologist at the University of Florence in Italy, show new evidence that plants can be so they see.
The first point the researchers make is that in 2016 it was discovered that the cyanobacterium Synechocystis has the ability to act as an ocellus. Cyanobacteria, which were previously also known as blue-green algae, form a biological category (a cut) comprising single-celled organisms that have the ability to photosynthesize. Being prokaryotic cells, it is wrong to think of them as algae, a term limited to a few eukaryotic cells.
The mechanism used by Synechocystis to generate vision is based on a curious trick: he uses his own body as if it were a lens to project an image of light that crosses its cell membrane, just like the retina in animals. Baluska believes that if such an ability exists in such primitive beings, it may be that in higher plants there is a possibility that they exhibit a similar mechanism.
Other evidence in favor
Other points highlighted by these researchers are based on recent studies which reveal that certain plants, such as cabbage or mustard, make proteins involved in the development and functionality of eye spot or stigma, a class very simple eyepiece that is present. some single-celled organisms such as green algae, which capture information about the direction of light.
these proteins they are specifically part of the structure of plastoglobulesThe vesicles that are inside the chloroplast (cell organelle responsible for photosynthesis) and function is a mystery. Baluska suggests that this finding could reveal that the plastoglobules act as if they were an eye spot for higher plants.
Other observations made by the researchers abandon the idea that the ability of plants to see can use systems completely different from what we currently know in complex organisms, being currently beyond our comprehension. For example, in 2014 a study emerged which showed that the climbing plant Boquila trifoliolata can change the color and shape of its leaves, mimicking those of the supporting plant. It is not known what mechanism is used to achieve this mimicry.
Despite everything that has been said, at the end of the day, this is evidence and not a description of the specific mechanism that plants would use to see. However, this opens the door to a new avenue of research around plant physiology and biology in the search for whether there can really be one or more methods for capturing visual information from the medium, a resource that would allow higher plants to have a sense of vision. , just like a bacteria such as Synechocystis.